Influence of Mn and Fe Addition on the NO x Storage–Reduction Properties and SO2 Poisoning of a Pt/Ba/Al2O3 Model Catalyst

Abstract

This work deals with the effect of Mn or Fe addition on the NO x storage-reduction properties of a Pt/Ba/Al 2 O 3 model catalyst. NO x storage capacity, SO 2 poisoning and regeneration and NO x removal efficiency under rich/lean cycling conditions are studied. Fe addition to Pt/Ba/Al 2 O 3 leads only to a small increase of NO x storage capacity, and more interestingly, to a better sulfur removal due to the inhibition of bulk barium sulfate formation. Unfortunately, the NO x storage property cannot be fully recovered. Moreover, Fe addition results in a decrease in the NO x removal efficiency. Mn addition also improves the NO x storage capacity, but no significant influence on the sulfur elimination is observed. Mn-doped catalyst does not improve the NO x removal efficiency, but NH 3 selectivity is found to drastically decrease at 400°C, from 20 to 3%. In addition, the NO x conversion can be improved at higher H 2 concentration in the rich pulse, always keeping NH 3 selectivity at low level.

NOx removal efficiency and ammonia selectivity during the NOx storage-reduction process over Pt/BaO(Fe, Mn, Ce)/Al2O3 model catalysts. Part II: Influence of Ce and Mn–Ce addition

“…It varies between 22 and 4% for Pt/20BaCe0.25/Al and Pt/20BaCe2/Al, respectively. These results are consistent with those obtained previously with Pt/CexZr1-xO2 catalysts[30]. It was demonstrated that the ammonia selectivity obtained in similar condition test was dependant of the ceria-zirconia composition.…”

“…Concerning the ammonia selectivity, cerium could lead to lower emission. Indeed, in a recent work about the NOx storage reduction (NSR) behavior of Pt/CexZr1-xO2 catalysts, it was observed that the ammonia selectivity decreases with the increase of the cerium loading [30]. Thus, the aim of the present work is to examine the influence of Ce addition on the NSR efficiency of Pt/Ba/Al model catalyst, with a special attention for the ammonia emission.…”

“…Nevertheless, the activity improvement obtained by cerium addition should be not attributed only to its OSC properties. Indeed, in a recent study, Pt/CexZr1-xO2 catalysts were studied [30].…”

PtM/Ba/Al2O3Ce0.6Zr0.4O2: Influence of Synergetic Interactions between Transition Metal and Platinum on NOx Storage and Reduction

“…Manganese oxide was reported to produce similar promotional effects on NSC, but no significant influence on sulfur resistance was observed 8. The addition of iron oxide was reported to improve sulfur resistance in Pt/Ba/Al 2 O 3 through inhibiting the formation of bulk barium sulfates 6a. 9 However, the co‐presence of Fe and Pt usually results in a strong deactivation 8b.…”

Crystallization pathways, morphologies and structural defects of α-MnO2 nanomaterial synthesized under annealed temperatures

“…1 shows the TPR-H2 profiles of the A, A200, A400, and A600 samples. It is worth mentioning that the reduction of MnO2, in general, should be proceeded through three stages 18,19,26,28 . First, MnO2 is converted to Mn2O3 (Eq.…”